Re: Oase BIOTEC 4 ! ! ! !
#2
"Boitec 4: is a four step filter and smallest in all available OASE Biotec range"
Doesn't look too great, if I was you i'd go on ebay and look for a small multibay - you will probably be able to get one cheap. Other, take a look at the Yamitsu Mega boxes, I got one and they are very good. Believe me its better to pay more and do it right first time as I have found out the hard way.
As for a UV, you can buy a standalone UV such as the Yamistu 25w which would probably be suitable for the size of your pond. Standalone UV's tend to be better than ones built into boxes.